better than a spark test: do a voltage drop reading........
Disconnect negative battery cable. Connect the red lead of an ANALOG voltmeter to the negative cable, the black lead to the negative terminal (on battery). Should read less than 2 volts, more if you have modern stereo with memory or clock, alarms,...
I realize that this is an old post, but I’m experiencing this problem on my ’53 3100 (converted to 12V with an alternator) and I want to try this troubleshooting suggestion.
But I’m not sure I understand it correctly. It sounds like you’re putting the voltmeter in series with the battery. I thought you always measured voltage drop in parallel. Maybe that’s not a problem if it’s only a couple of volts, but what’s that going to do to my meter (digital not analog) if it’s a higher voltage or high current?
